[CVE-2026-64488][LOW] ALSA: aoa: check snd_ctl_new1() return value [ Upstream

[AL-KERNEL <alkernel@kernelcve.org>]

CVE: CVE-2026-64488
Priority: LOW
AL-KERNEL base severity: LOW
KPANIC flag: NO
Patch: ALSA: aoa: check snd_ctl_new1() return value [ Upstream
Commit: b0154ebc6dc552c389a574b1e221d728e10346e7
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b0154ebc6dc552c389a574b1e221d728e10346e7
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64488
Analysis date: Sat, 25 Jul 2026 08:30:39 -0400
ActionableScore: 1
ActionableScore lower bound: 0
Actionable bucket: Ordinary Moderate / Low-like
Manual review required: NO

Summary:
ALSA AOA may dereference a NULL snd_kcontrol pointer after an allocation failure in snd_ctl_new1() during codec attach, causing a local crash-only DoS on rare affected hardware.

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ABOUT THIS REPORT
======================================================================

The original Linux kernel CVE announcement for CVE-2026-64488 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64488

The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.

The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.

Published priority for this report: LOW
Manual review required: NO

A detailed explanation of the methodology and priority rules is included
at the end of this message.

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-64488	LOW	CHECK WITH IMPACT FROM ORIG NN LOW	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H';**CWE-476;CWE-252;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';BEST CVSS score: '4.7';DESCR 'ALSA aoa can dereference a NULL snd_kcontrol pointer because snd_ctl_new1() may fail during allocation and layout_attached_codec can still access ctl.id.name or pass ctl to aoa_snd_ctl_add. The trigger depends on an out-of-memory condition during AOA codec attach or driver probe, so reliable exploitation is difficult and tied to local system state rather than remote input. For the CVSS the PR:L is used for the paranoid score because a local user may be able to contribute to memory pressure while the driver attach path is reached by system activity, although the base case is closer to PR:H when module loading or reprobe control is required. The issue is not network reachable. Impact is denial of service via kernel crash only, with no supported path to information disclosure or privilege escalation.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 1)  SKIP CVE-2026-64488 UNKNOWN SKIP No affected files built, so skip this CVE NO  - - unknown 	MAYBE	NULLPTR SIMPLEFIX HARDWARE LINUS  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS_AND_CIANNH DECREASED_TO_LOW_FROM_MODERATE_BASED_ON_ACTIONABLESCORELESSTHAN3	-	-	checked

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ACTIONABLESCORE ANALYSIS
======================================================================

ActionableScore=1
ActionableScoreLower=0

## 1. ActionableScore

* Conservative score: 0
* Paranoid score: 1
* Final recommended bucket: **Ordinary Moderate / Low-like**

## 2. Signal breakdown

Triggered signals:

* Reliable kernel crash / strong DoS: +1
  `snd_ctl_new1()` may return NULL and the old code can dereference `ctl->id.name` or pass NULL to `aoa_snd_ctl_add()`, causing a NULL pointer dereference.

Negative / limiting signals:

* Requires admin/root or privileged device reprobe in typical deployments: -2
  Reliable triggering normally requires driver probe, reprobe, module/device control, or a controlled low-memory condition during AOA codec attach.
* Rare hardware / non-broad exposure: -1 or -2
  ALSA AOA is a niche Apple Onboard Audio path and not a broad default server/workstation attack surface.
* Hard or unreliable condition: -1
  The failure requires allocation failure at a narrow point during codec attachment.

Not awarded:

* No generic memory corruption bonus. This is a NULL dereference, not UAF, OOB write, double free, or type confusion.
* No privilege escalation plausibility. No reclaim, overwrite, callback control, refcount abuse, or object replacement is shown.
* No confidentiality or integrity impact. The primitive is crash-only.
* No network reachability.

## 3. Reachability analysis

The bug is reachable only when the AOA audio driver attaches a codec and `snd_ctl_new1()` fails due to memory allocation failure. A normal local unprivileged user does not directly invoke this path reliably. A paranoid interpretation gives limited credit to local memory-pressure influence, but the attach/probe condition is still not under ordinary unprivileged control. Containers and namespaces do not meaningfully improve reachability unless they also allow device/module management, which is not typical. The subsystem is hardware-specific and uncommon.

## 4. Severity interpretation

This behaves like ordinary Moderate or Low-like kernel DoS, not Important. The theoretical failure mode is a kernel NULL pointer dereference and crash. There is no evidence of practical memory corruption, privilege escalation, information disclosure, or cross-boundary security bypass.

## 5. One-sentence report phrase

ALSA AOA may dereference a NULL snd_kcontrol pointer after an allocation failure in snd_ctl_new1() during codec attach, causing a local crash-only DoS on rare affected hardware.

## 6. Manual review recommendation

NO MANUAL CHECK NEEDED

This can be auto-closed or handled in deferred routine patching because it is a rare hardware-specific NULL dereference with crash-only impact and no supported LPE or memory-corruption primitive.

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UPSTREAM PATCH SUMMARY
======================================================================

Patch: ALSA: aoa: check snd_ctl_new1() return value [ Upstream
Commit: b0154ebc6dc552c389a574b1e221d728e10346e7
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b0154ebc6dc552c389a574b1e221d728e10346e7

Changed files:
  sound/aoa/fabrics/layout.c

Diff excerpt:

Not included in this email. See the upstream URL for the full patch.

Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b0154ebc6dc552c389a574b1e221d728e10346e7

======================================================================
DETAILED REPORT METHODOLOGY
======================================================================

The original Linux kernel CVE announcement for CVE-2026-64488 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-64488

The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.

The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.

The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.

Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:

  Conservative CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.7

The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.

CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.

A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.

  Conservative ActionableScore: 0
  Paranoid ActionableScore: 1

The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.

For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:

  ActionableScore below 5   -> MODERATE REGULAR
  ActionableScore 5 or more -> MODERATE 7.0

The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.

There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).

KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.

AL-KERNEL base severity for this report: LOW
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): LOW

These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).

Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).